Hi guys,I am here new one,but I read this forum over one year and I have fundamental question(like boys on Apollo 13):is here somebody,who love "notsimplicity" circuity?What I mean:circuity,especial power amplifiers,where are every details made in mode "state of art" and I say again every details.When I was younger,I was happy when I saw circuity of Tom Collangelo,Erno Borbelly,Robert Cordell,Malcolm Hawksford and many others-it was for me victory of brain against matter.Now I am studing datasheets of OA's,where only I see "similar victory".In my opinion " apostle of simplicity"Nelson Pass lead people to the wrong way and many people mean,that with one transistor (!) will be Heaven on the Earth.Fortunately is here people like Bruce Candy of Halcro,who have still brain on the head(look at his US patent-enjoy!).Many people here quote Douglas Self or prof. Leach,but it is circuity,which was modern before approximately fifteen years.Some people here makes pretty nice machines(Peranders,Jan Dunlop etc.) and I have question:have somebody here the same "love" like I have?I construct amplifier over twonyfive years and I know,that simplicity is not(in most of times) the righ way and with this statement I will stand alone.In the end of my "overture" guys,beg your pardon for my english-most of my life I spend on east ,but I hope that will be better.My name is Pavel Dudek,I am living in Prague in Czech Republic (for american guys:it is in middle of Europe) and my job is developement of electronic.P.S.:I am computer idiot.

I am not clear what you want. Do you want simple? Do you want obsolete, you know, from the old days? This is it: Simple is good. Sophisticated and simple is better. Too complex, is interesting, but problematic. Choose for yourself.

Originally posted by john curl I am not clear what you want. Do you want simple? Do you want obsolete, you know, from the old days? This is it: Simple is good. Sophisticated and simple is better. Too complex, is interesting, but problematic. Choose for yourself.

What he tries to say is that similar results are not achievable with simple topology. These results are achievable only in case that you reduce distortion in every amp's stage, which is perfectly impossible in simple topology. On the other hand - difficult way for DIYers, I agree.

>In my opinion "apostle of simplicity" Nelson Pass lead people to the wrong way.<

You may not agree with Nelson's way, but the ease of building simple designs like the Zen family and the Gainclone variants has undoubtedly been a major factor in enticing many people into trying their hand at building amplifiers, whereas more complex designs would in all likelihood be too intimidating for most beginners. All of us were beginners at one time, and no matter how much progress we may make, we should never forget what it feels like to be a beginner. You cannot be a good parent if you have forgotten what it is like to be a child, isn't this so?

My opinion is that the most important things are whatever goals that _you_ decide that you want to achieve, with success measured in terms of how closely the end-results align with your defined goals. Complexity, simplicity, tubes, discrete semiconductors, ICs, switching-mode operation; these are all tools for us to use in trying to achieve our goals, and should not be construed as being holy grails unto themselves. My advice is to use whatever approaches, tools or methods you think offer the best chance for you to attain your goals. And if the end-results fall short of your initial goals, analyze what went wrong and try again. Making mistakes is an essential part of learning.

In general, I enjoy complex, sophisticated electronics designs far more than simple ones, and I would certainly like to see other designs that demonstrate a lot of thought and innovativeness.

But that is a reflection of my personality and my preferences. I have no illusions that this is the best approach for anyone except myself.

Originally posted by jcarr In general, I enjoy complex, sophisticated electronics designs far more than simple ones, and I would certainly like to see other designs that demonstrate a lot of thought and innovativeness.

But that is a reflection of my personality and my preferences. I have no illusions that this is the best approach for anyone except myself.

Bravo, Jonathan. Such words are a breath of fresh air compared to the stifling absolutism and intolerance of individuality and diversity that is too often preached by others.

Upupa, I understand you now. Well, it is difficult to give difficult circuits to amateurs.
Halcro is my greatest and most direct competitor. I liked the sound that they produced at the CES with the Dave Wilson speakers.
They have AMAZING specs. Better than anything that I will ever do. However, they would be almost impossible to reproduce easily. This is real engineering! It requires proper layout and individual compensation at each stage. This is almost impossible without a real company behind you.
Go ahead if you must, but you might as well try to make a Porsche on your own, as to make a Halcro. It is cheaper and easier just to buy one. Become a dealer in your area, get it at wholesale or better.

Originally posted by john curl Upupa, I understand you now. Well, it is difficult to give difficult circuits to amateurs.
Halcro is my greatest and most direct competitor. I liked the sound that they produced at the CES with the Dave Wilson speakers.
They have AMAZING specs. Better than anything that I will ever do. However, they would be almost impossible to reproduce easily. This is real engineering! It requires proper layout and individual compensation at each stage. This is almost impossible without a real company behind you.
Go ahead if you must, but you might as well try to make a Porsche on your own, as to make a Halcro. It is cheaper and easier just to buy one. Become a dealer in your area, get it at wholesale or better.

John,

nice post, thanks for it. Upupa is a remarkable designer and he reached similar parameters as Halcro (a little bit worse, but not much) some 10 years ago. But in the past our "two worlds" were separated and bi-directional exchange of information has started few years ago. Halcro is a great challenge for him. We are doing comparative listening tests of well known famous world amplifiers in high quality audio chains (with speakers like Wilson Audio Maxx), but never had a chance to hear Halcro ...

Actually, each amplifier design has a number of tradeoffs. It is fairly easy to make an amplifier that has almost no distortion. This is done by negative feedback, both local and loop. It can also be done with feed-forward, or the Quad 'current dumping' type circuit.
Each designer must decide what sounds best: ultra-low distortion, single ended, open loop operation, class A, etc. No one approach is necessarily better in every way, from the others. This is about all that I have to say on the subject.

John is right, It depends on what you want to do and how you will use it. I like things to be simple and work well but not too many people can hear the things that a computer and test gear can, so where is the balance of the two? You can build the most linear, most efficient, highest parts count, expensive, complicated, scientific marvel amp, but if my human ears can't tell the difference, what's it all for anyway. OK, you have the best specs ever achieved in amplifier technology, but for what? Bragging rights? Good for you but that won't change the fact that 98% plus, of the population physically won't be able to hear the difference and your $30,000.00 amp will be yours and yours alone, while the rest of us are happy with a $500.00 amp we built ourselves or bought from the electronics store, with even lower specs than most of us DIY people have.

I'm not trying to be a jerk. I'm just trying to be realistic and practical here. I do agree with you. It sometimes takes some pretty fancy circuitry to get the best of results.